03-21. Airworthiness Directives; McDonnell Douglas Model DC-10-10 and DC-10-10F Airplanes; Model DC-10-15 Airplanes; Model DC-10-30, DC-10-30F, and DC-10-30F (KC10A and KDC-10) Airplanes; Model DC-10-40 and DC-10-40F Airplanes; and Model MD-10-10F ...

AGENCY:

Federal Aviation Administration, (DOT).

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas airplane models, that would have required an inspection of the throttle control module on the center pedestal in the flight deck compartment to determine its part number and configuration, and modification of the throttle control module. This new action revises the proposed rule by adding additional repetitive inspections for chafing of the throttle control module wiring and adding additional airplanes to the applicability of this AD. The actions specified by this new proposed AD are intended to prevent chafing of wiring inside the throttle control module, fuel shutoff lever lights, and/or aft pedestal lightplates due to degradation of protective sleeving, which could result in electrical arcing and failure of the auto throttle/speed control system and consequent smoke and/or fire in the cockpit.

DATES:

Comments must be received by January 28, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-99-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425)-227-1232. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-99-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Technical Information: Natalie Phan-Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

Other Information: Judy Golder, Airworthiness Directive Technical Editor/Writer; telephone [phone], fax [phone]. Questions or comments may also be sent via the Internet using the following address: [e-mail]. Questions or comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-99-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-99-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10-10 and DC-10-10F airplanes; Model DC-10-15 airplanes; Model DC-10-30, DC-10-30F, and DC-10-30F (KC10A and KDC-10) airplanes; Model DC-10-40 and DC-10-40F airplanes; and Model MD-10-10F and MD-30F airplanes, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on August 24, 2001 (66 FR 44562). That NPRM would have required an inspection of the throttle control module (TCM) on the center pedestal in the flight deck compartment to determine its part number and configuration, and modification of the TCM. Those actions are necessary to prevent chafing of wiring inside the TCM, fuel shutoff lever lights, and/or aft pedestal lightplates due to degradation of protective sleeving, which could result in electrical arcing and failure of the auto throttle/speed control system and consequent smoke and/or fire in the cockpit.

Since the Issuance of the NPRM

Since the issuance of that NPRM, the FAA has reviewed and approved Boeing Alert Service Bulletin (ASB) DC10-76A049, including Appendix and Evaluation Form, all dated January 29, 2002. That ASB describes procedures for repetitive visual inspections for chafing or potential chafing of wiring of the TCM module located on the center pedestal in the flight compartment. That ASB also describes procedures for repairing or repositioning electrical wiring, as applicable, if necessary.

In addition, the FAA has reviewed and approved Boeing ASB DC10-76A048, Revision 01, dated January 29, 2002, including Evaluation Form. (Boeing ASB DC10-76A048, dated August 6, 2001, was specified as the appropriate source of service information in the NPRM.) Boeing ASB DC10-76A048, Revision 01, dated January 29, 2002, adds two airplanes to the effectivity and describes procedures that are generally the same as the original service bulletin. The procedures described in Revision 01 of the ASB are for an inspection of the TCM on the center pedestal in the flight deck compartment to determine its part number and configuration, and modification of the TCM. The modification includes removing material from the throttle lever and cover plates (as applicable) for engines 1, 2, and 3; replacing the existing guide assembly with an improved guide assembly inside the TCM; replacing the existing protective sleeving on the wire bundles; removing previously installed spiral wrap tubing on the auto throttle/takeoff/go around (TOGA) wiring; and reidentifying the coverplates and TCM; as applicable.

Accomplishment of the actions specified in those service bulletins is intended to adequately address the identified unsafe condition.

Comments

Due consideration has been given to the comments received in response to the NPRM.

Requests To Extend Compliance Time

Three commenters request that the compliance time for the modification that would be required by paragraph (a) of the proposal be extended from 18 months to 5 years. Two commenters state that there may be a problem with parts availability, and that they would be unable to meet an 18-month compliance time. Additionally, the commenters note that a 5-year compliance time would also align with the modification of the thrust reverser activation system (TRAS) that is required by AD 2001-17-19, amendment 39-12410 (65 FR 44950, August 27, 2001). That AD requires the TCM to be removed in order to access the TRAS. One commenter requests that, for certain airplanes, the compliance time be extended to 36 months. That commenter did not provide any justification for the extension. One commenter, the manufacturer, states that it has released a new service bulletin (Boeing ASB DC10-76A049, including Appendix and Evaluation Form, all dated January 29, 2002, as described earlier in this Supplemental Notice of Proposed Rulemaking (SNPRM)) that specifies repetitive visual inspections for chafing or potential chafing of the TCM wiring located on the center pedestal in the flight compartment. The manufacturer states that, if the repetitive inspections described in the new service bulletins are accomplished every 18 months, a 5-year compliance time for the modification should be adequate to ensure operational safety of the affected airplanes.

The FAA agrees with certain commenters that the compliance time may be extended for the reasons they specified. We have revised the original NPRM to extend the compliance time for the modification until 5 years after the effective date of the AD. Additionally, we have added a new paragraph (a) to this SNPRM that specifies repetitive visual inspections for chafing or potential chafing of the wiring every 18 months, until the modification is accomplished.

Requests to Withdraw the NPRM

Two commenters disagree with a need for the rule as proposed. The commenters state that they are unaware of any report of smoke or fire in the cockpit of the Model DC-10 fleet that resulted from wire chafing in the TCM. The commenters conclude that supporting documentation of such incidents of smoke or fire is absent. The FAA infers that the commenters are requesting that the original NPRM be withdrawn.

The FAA does not agree. We acknowledge that we are unaware of any specific reports of smoke or fire due to wire arcing or chafing associated with the TCM on the airplanes specified in this SNPRM. However, we find that there have been numerous incident reports describing wire chafing that emanated from other systems, which has been identified as the ignition source for some in-flight smoke and/or fires. Therefore, we consider that an unsafe condition has been identified that is likely to exist or develop on other products of these type designs, and that issuance of this SNPRM is warranted.

Requests to Revise the Cost Impact Section

The commenters request that the Cost Impact section be revised to reflect a more realistic work hour estimate of 24 hours for the accomplishment of the modification. (The original NPRM estimates between 4 and 7 hours.)

The FAA agrees that the cost information should be revised. However, we have revised the estimated cost for accomplishing the modification based on the current work hours estimated in Boeing ASB DC10-76A048, Revision 01, dated January 29, 2002. The estimated work hours to accomplish the modification specified in that service bulletin (excluding work hours to remove, install, and test) are approximately 15 work hours. We estimate that the average labor rate is $60 per work hour, and that required parts would cost approximately $1,712 per airplane. Based on those figures, we estimate that the modification cost impact of the proposed AD would be $2,612 per airplane.

Additionally, we have added an estimated cost of the inspection specified in Boeing ASB DC10-76A049, dated January 29, 2002. We estimate that each inspection would take 2 work hours to perform, at an estimated average labor rate of $60 per work hour, per inspection. Based on those figures, we estimate that each inspection would cost approximately $120 per airplane, per inspection cycle.

Explanation of New Requirements of Proposal

Since an unsafe condition has been identified that is likely to exist or develop on other products of these type designs, this SNPRM would continue to require an inspection of the TCM on the center pedestal in the flight deck compartment to determine its part number and configuration, and modification of the TCM. This SNPRM also would add repetitive inspections for chafing or potential chafing of the TCM wiring, and corrective actions if necessary. This SNPRM also would require adding airplanes to the applicability of this AD. The actions would be required to be accomplished in accordance with the service bulletins described previously.

Conclusion

Since these changes expand the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Explanation of Change to Applicability

The FAA has revised the applicability of the original NPRM to identify model designations as published in the most recent type certificate date sheet for the affected models.

Cost Impact

There are approximately 401 McDonnell Douglas Model DC-10-10 and DC-10-10F airplanes; Model DC-10-15 airplanes; Model DC-10-30, DC-10-30F, and DC-10-30F (KC10A and KDC-10) airplanes; Model DC-10-40 and DC-10-40F airplanes; and Model MD-10-10F and “MD-10-30F airplanes; of the affected design in the worldwide fleet. The FAA estimates that 321 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 15 work hours per airplane to accomplish the proposed modification, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,712 per airplane. Based on these figures, the cost impact of the modification proposed by this AD on U.S. operators is estimated to be $838,452 or $2,612 per airplane.

We estimate that it would take approximately 2 work hours per airplane to perform the proposed inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspections proposed by this AD on U.S. operators is estimated to be $38,520, or $120 per airplane, per inspection cycle.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) Is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

McDonnell Douglas: Docket 2001-NM-99-AD.

Applicability: Model DC-10-10 and DC-10-10F airplanes; Model DC-10-15 airplanes; Model DC-10-30, DC-10-30F, and DC-10-30F (KC10A and KDC-10) airplanes; Model DC-10-40 and DC-10-40F airplanes; Model MD-10-10F and MD-10-30F airplanes; as listed in Boeing Alert Service Bulletin DC10-76A048, Revision 01, dated January 29, 2002; certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent chafing of wiring inside the throttle control module, fuel shutoff lever lights, and/or aft pedestal lightplates due to degradation of protective sleeving, which could result in electrical arcing and failure of the auto throttle/speed control system and consequent smoke and/or fire in the cockpit; accomplish the following:

Repetitive Inspections for Chafing

(a) Within 18 months after the effective date of this AD, perform a general visual inspection for chafing or potential chafing of the wiring of the throttle control module located on the center pedestal in the flight compartment, per Boeing Alert Service Bulletin (ASB) DC10-76A049, excluding the Appendix and Evaluation Form, all dated January 29, 2002. Thereafter, repeat the inspection at intervals not to exceed 18 months, until the actions specified in paragraph (c) of this AD are accomplished.

Note 2:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(b) If any evidence of chafing or potential chafing is found during any inspection required by paragraph (a) of this AD, before further flight, repair the chafed wires or reposition wires, as applicable, per Boeing ASB DC10-76A049, excluding the Appendix and Evaluation Form, all dated January 29, 2002.

Inspection and Modification

(c) Within 5 years after the effective date of this AD, do the actions specified in paragraphs (c)(1) and (c)(2) of this AD, per Boeing ASB DC10-76A048, excluding the Evaluation Form, both dated August 6, 2001; or Revision 01, excluding the Evaluation Form, both dated January 29, 2002.

(1) Do an inspection of the throttle control module on the center pedestal in the flight deck compartment to determine its part number and configuration, which will identify the group applicability information.

(2) Modify the throttle control module on the center pedestal in the flight deck compartment per the applicable figure in the service bulletin. Accomplishment of the modification constitutes terminating action for the requirements of paragraph (a) of this AD.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permit

(e) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on December 24, 2002.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.